Feuling Adjustable Pushrods 4065 Increased stiffness and column rigidity maximizing valve-train stability, increasing engine RPM horsepower and torque output Made from 7/16in. chrome moly steel tube, uses a minimal adjustment parameter eliminating the flex and loss of valve train-stability problems associated with most adjustable pushrods Designed to exceed the needs of performance engines using larger lift camshafts and high spring pressures, while maintaining proper and critical oil flow to valves, springs, rockers, shafts and valve guides Maintain maximum valve lift Can be used with hydraulic or solid lifters and street or race engines